Matrix: MathWorks/Kaufhold

Description: John Kaufhold, GE. Triggers bug in LU in MATLAB 6.5 on Windows (not Linux)

MathWorks/Kaufhold graph
(undirected graph drawing)

MathWorks/Kaufhold dmperm of MathWorks/Kaufhold

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  • Matrix group: MathWorks
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  • download as a MATLAB mat-file, file size: 306 KB. Use UFget(1404) or UFget('MathWorks/Kaufhold') in MATLAB.
  • download in Matrix Market format, file size: 439 KB.
  • download in Rutherford/Boeing format, file size: 392 KB.

    Matrix properties
    number of rows8,765
    number of columns8,765
    structural full rank?yes
    structural rank8,765
    # of blocks from dmperm256
    # strongly connected comp.256
    explicit zero entries0
    nonzero pattern symmetrysymmetric
    numeric value symmetry 78%
    Cholesky candidate?no
    positive definite?no

    editorT. Davis
    kindcounter-example problem
    2D/3D problem?no

    Ordering statistics:result
    nnz(chol(P*(A+A'+s*I)*P')) with AMD46,565
    Cholesky flop count4.4e+05
    nnz(L+U), no partial pivoting, with AMD84,365
    nnz(V) for QR, upper bound nnz(L) for LU, with COLAMD99,409
    nnz(R) for QR, upper bound nnz(U) for LU, with COLAMD204,810

    SVD-based statistics:
    null space dimension6
    full numerical rank?no
    singular value gap2.29824

    singular values (MAT file):click here
    SVD method used:s = svd (full (A)) ;

    MathWorks/Kaufhold svd

    For a description of the statistics displayed above, click here.

    Maintained by Tim Davis, last updated 12-Mar-2014.
    Matrix pictures by cspy, a MATLAB function in the CSparse package.
    Matrix graphs by Yifan Hu, AT&T Labs Visualization Group.